Yilashan ophiolite, located in the middle section of the Bangong lake- Nujiang suture zone, contains predominantly strongly- altered harzburgite and dunite, as well as podiform chromitite.The chromitite orebodies in the Yilashan area are mainly distributed in the northern part of the ophiolite, and consist mainly of dunite with minor amount of harzburgite. Electron microprobe analysis shows that the chromian spinel in the Yilashan chromite has Cr# values of 64. 2~73. 9, 46. 9~71. 6 of Mg#, TiO2 of 0. 03%~0. 31%, Al2O3 of 4. 5%~18. 7%, indicating that the Yilashan chromite should be high- Cr type chromite. The distribution patterns of REEs and trace elements of the Yilashan harzburgite are indicative of abyssal peridotite.The platinum group elements of chromite show enrichment of IPGE and depletion of PPGE, with right- dipping distribution patterns and no clear correlation between Pd/Ir and Pt/Pt*, reflecting that the Yilashan ophiolite had experienced the rock- melt reaction.Comparison study with other chromite ores suggests that the Yilashan chromite may be formed by the reaction of boninite melt with rocks in the subduction belt environment and undergo a multi- stage evolution process, i.e. the early MORB environment and the transformation of the late suprasubduction zone (SSZ).